1. Field of the Invention
The present invention relates to a DC/DC converter and electronic apparatus.
2. Description of the Related Art
A DC/DC converter for converting a DC voltage of a predetermined voltage value into that of another voltage value is known. The DC/DC converter controls an output voltage to be constant by, for example, ON/OFF-controlling a switching element. Such DC/DC converter includes, for example, an overheat protection function for protecting the switching element from an abnormal overheat state.
As a related technique for protecting a switching element from an abnormal overheat state, Japanese Patent Laid-Open No. 2002-142449 refers to an overheat protection circuit having a PTC (Positive Temperature Coefficient) thermistor. With this technique, for example, the PTC thermistor (overheat detection element) is thermally coupled to the switching element via, for example, a silicon resin RS. When the PTC thermistor exceeds a Curie temperature, the resistance value of the thermistor increases, and the switching element is consequently turned off. Then, the switching element is protected from an overheat state.
However, in the technique disclosed in Japanese Patent Laid-Open No. 2002-142449, when a component other than the switching element is to be overheat-protected, an overheat detection element and protection circuit for stopping the switching operation of the switching element have to be newly added. For this reason, many components have to be added, resulting in an increase in cost.